High-viscous lubricant copolymer compatible with non-polar base fluids

Abstract

The invention pertains to a lubricant or lubricant additive having a viscosity ranging from 200 to 1100 cSt which at the same time is compatible with non-polar base fluids such as poly(α-olefins), and which comprises a copolymer of an α-olefin having of from 8 to 18 carbon atoms and a fumaric diester having an aliphatic alcohol as the esterifying component, the copolymer having a weight average molecular weight above approximately 3500, and the esterifying component being C 8 to C 10 alcohol (linear or branched) or iso-C 13 alcohol. Also disclosed is a process for the preparation of the copolymers wherein an α-olefin having of from 8 to 18 carbon atoms is reacted with a fumaric diester under the influence of a peroxide radical initiator having tertiary alkyl groups while applying a temperature of from 110° C. to 150 ° C.

What is claimed is  
     
         1 . A lubricant or lubricant additive comprising a copolymer of an α-olefin having from 8 to 18 carbon atoms and a fumaric diester having an aliphatic alcohol as the esterifying component, wherein the copolymer has a weight average molecular weight above approximately 3500 and a viscosity at 100° C. above about 200 centistokes, and wherein the esterifying component is selected from the group consisting of linear octanol, branched octanol, linear nonanol, branched nonanol, linear decanol, branched decanol, branched tridecanol, and mixtures thereof.  
     
     
         2 . The lubricant or lubricant additive of  claim 1  wherein the copolymer has a viscosity at 100° C. of from about 300 centistokes to about 1100 centistokes.  
     
     
         3 . A lubricant additive comprising a copolymer of an α-olefin having of from 8 to 18 carbon atoms and a fumaric diester having an aliphatic alcohol as the esterifying component, wherein the copolymer has a weight average molecular weight above approximately 3500 and a viscosity at 100° C. above about 200 centistokes, and wherein the esterifying component is a C 8  to C 10  alcohol.  
     
     
         4 . The lubricant additive of  claim 3  wherein the copolymer has a viscosity at 100° C. of from about 300 centistokes to about 1100 centistokes.  
     
     
         5 . A lubricant additive comprising a copolymer of an α-olefin having of from 8 to 18 carbon atoms and a fumaric diester having an aliphatic alcohol as the esterifying component, wherein the copolymer has a weight average molecular weight above approximately 3500 and a viscosity at 100° C. above about 200 centistokes, and wherein the esterifying component is iso-C 13  alcohol.  
     
     
         6 . The lubricant additive of  claim 5  wherein the copolymer has a viscosity at 100° C. of from about 300 centistokes to about 1100 centistokes.  
     
     
         7 . The lubricant or lubricant additive according to  claim 1  wherein the α-olefin has 12 to 16 carbon atoms.  
     
     
         8 . The lubricant or lubricant additive of  claim 7 , wherein the esterifying component is iso-C 10  alcohol.  
     
     
         9 . The lubricant or lubricant additive of  claim 7 , wherein the esterifying component is iso-C 8  alcohol.  
     
     
         10 . A lubricating oil composition comprising a poly(α-olefin) and from 1 to 70 wt %, of a lubricant additive in accordance with  claim 1 .  
     
     
         11 . A process for the preparation of a copolymer of an α-olefin and a fumaric diester, the copolymer having a weight average molecular weight above approximately 3500, wherein an α-olefin having from 8 to 18 carbon atoms is reacted with a fumaric diester under the influence of a peroxide radical *initiator while applying elevated temperature, wherein the temperature is kept within the range of from 110° C. to 150° C.  
     
     
         12 . The process of  claim 11  wherein the temperature is kept between 120° C. and 140° C.  
     
     
         13 . The process of  claim 11  wherein the peroxide is t-butylperoxy-3,5,5-trimethylhexanoate.  
     
     
         14 . A copolymer of an α-olefin having of from 8 to 18 carbon atoms and fumaric diester having an aliphatic alcohol as the esterifying component which has a weight average molecular weight above approximately 3500, prepared in accordance with the process of  claim 11 .  
     
     
         15 . The copolymer of  claim 14  wherein the copolymer has a viscosity at 100° C. above about 200 centistokes.  
     
     
         16 . A copolymer of an α-olefin and a fumaric diester having an aliphatic alcohol as the esterifying component, wherein the copolymer has a weight average molecular weight above approximately 3500 and a viscosity at 100° C. above about 200 centistokes, the α-olefin has 8 to 12 carbon atoms, and wherein the esterifying component is iso-C 8  alcohol.  
     
     
         17 . The copolymer of  claim 16  wherein the copolymer has a viscosity at 100° C. of from about 300 centistokes to about 1100 centistokes.  
     
     
         18 . A copolymer of an α-olefin and a fumaric diester having an aliphatic alcohol as the esterifying component, wherein the copolymer has a weight average molecular weight above approximately 3500 and a viscosity at 100° C. above about 200 centistokes, the α-olefin has 14 to 16 carbon atoms, and wherein the esterifying component is n-C 8  alcohol.  
     
     
         19 . The copolymer of  claim 18  wherein the copolymer has a viscosity at 100° C. of from about 300 centistokes to about 1100 centistokes.  
     
     
         20 . A lubricating oil composition comprising a poly(α-olefin) and from 5 to 50 wt % of a lubricant additive in accordance with  claim 1.